Phonograph record



Patented J... 14, 1936 PATENT OFFICE 2,028,126 rnonooaarn nncoan Richard F. Warren, Stratford, Conn.,-assi gnor to *Carbideand Carbon Chemicals Corporation, a

corporation of New York No Drawing. Application July 1, 1930,

, Serial No. 466,038

comm. (01.106-22l This invention relates to new and useful improvements in phonograph records. An object of the invention is to provide a phonographrecord which is light in weight; a record whichmay be repressed to have it carry a groove representing a different recording from that which it originally bore or which may bere-' pressed to have it carry the same groove in the 7 event of it having been rejected; or which may 1 be treated to provide it with a smooth surface by treating it with heat and pressure whereby to remove a groove in order that a groove may later be engraved in the smooth surface by means of a heated stylus or the like. A further object is to provide a record having an improvedsurface, that is, one wherein less scratch or less surface noise results from the tracking of the stylus in the record groove; a rec- 0rd which is hard in the sense that it will reproduce all audible frequencies and yet be flexible as a record, and which will withstand moisture.

Additional objects are to provide a record that may be pressed in a multiple press, and which may be pressed under areduced pressure as compared with pressures at present used, and which .is of such structm'e that itmay be cut from sheets as the record groove is-pressed.

Another object 'is to provide a record including. an improved surface coating adapted to receive the sound record groove, and which contains as the sole resinous constituent of the surface coating, a-vinyl resin, such as polymerized vinyl esters of the lower fatty acids, vinyl halidea'styrol, and

es thereof.

Other objects and advantages will become aparent from a consideration of the following dccription wherein the invention is fully disclosed.

However, it is to be understood that the inven- 7 tion is not limited to the details disclosed but com- .40 prehends all such changes as fall within the scope of the appended claims. 7

I have found that polymerized vinyl acetate or vinyl chloride, or mixtures of the two, with or without plasticizers, when used in the manufac-. 45 ture of phonograph records result in a record having a superior playing surface, in that it is hard and durable, and is particularly advantageous by reason of its freedom from surface noise.

Throughout this specification the invention will 50 be described as applied to a sheet of paper or the like, but it will be understood that it is also applicable to other-types of records, for example, it

may be used in solid stock records, or as a coating for sheets used in the manufacture of laminated 55 records. r

- In the manufacture of a record inaccordance with this invention, a sheet of fibrous material, whether in the form and size of a record, or larg- .er (for example, in the form of a roller strip) is first impregnated with a primary solution of 5 resinous material. For the purpose of this impregnation, the following procedure, may be used:

A fibrous material, such as paper or the like, which is to form the core of the record is impregnated or coated bypassing it through, or m otherwise, applying a solution of resinous material on its surface to provide a support or base for thesecond coating to be hereinafter described. This primary coating may be formed of any material or mixture of materials which will give the 15 fibrous core a smooth and hard moisture-resistant surface, but which will not render the sheet so hard and solid that it cannot later be compressed or flexed.

In my experiments I have found that a suitable 20 primary coating maybe applied by the'use of 'a solution of phenolic resin, such as phenol-formaldehyde or phenol-furfliraldehyde resins; cresolaldehyde resins; casein; cellulosic. derivatives, such as cellulose acetate or cellulose nitrate; and vinyl resins, such as polymerized vinyl acetate,

vinyl chloride, styrol or mixtures thereof. Other resinous materials than those named and combinations of the foregoing materials may also be used for the primary coating. In general, I pre- 30 fer to employ a heat-reactive artificial resin for the purpose of providing the record-core with a moisture-resistant surface. 7

For the phenolic and cresolic resins named above, alcohol may be used as a solvent. In the 35 use of casein, caustic soda or aqueous ammonia and other well known alkaline solvents may be employed. When cellulose esters, or the vinyl e resins are used,'acetone, diacetone alcohol, ethylene dichloride, and mixtures of these, or mix- 40 tures of these solvents with diluents such as toluene and benzbl may be used as the solvents.

It will of course be understood that the primary coating may be applied to the sheet other than by dipping. For example the primary coating may be sprayed onto the sheet or it may be applied with a brush or the like. Also, it is not absolutely necessary that the sheet be thoroughly impregnated. However, it is desirable that the surface of the sheet at least be impregnated so that the fibers thereof are coated, and the sheet made relatively moisture-resistant. Should the sheet not be moisture proof the fibres thereof on becoming wet will swell and may break the surface of the record. g

After being treated with the first or primary coating and dried, the sheet is given a second coating. The second coating consists essentially of the resinous material in which the record grooves are to be formed. In this connection it is to be noted that should the second coating beclude one or more of the following: Rottenstone,

clay, slate, barytes, red iron oxide, fullers earth, or umber. Coloring materials, such as lamp black, may be used if desired, and it is to be noted that red iron oxide, rottenstone, or umber may be used alone or in combination, and it is desirable to use one of the latter with the other materials mentioned.

The second coating composition may be made by adding the vinyl resin together with plasticizers and fillers, if desired, to a solvent and grinding the whole in a ball mill to obtain thorough dispersion. The solvent used, as has been indicated above, preferably is suificiently volatile in nature to be completely eliminated after the record is pressed. After the mixing operation, the mixture may be screened or filtered and is then ready for use.

The core which has been impregnated with the primary coating is then coated with the vinyl resin composition by any suitable means such as dipping-or spray ng, or the like. It is advantageous to incorporate a small amount of carnauba wax or lead salt master wax in the second coating solution in order that the record will have no tendency to stick when pressed.

When the second coating containing the vinyl resin is dry, the sheet may be'stamped or pressed The second coating was formed as follows: Vinyl resin (mixture of polymerized vinyl acetate and v vinyl chloride) 6 parts by weight Rottenstone 2 Lamp black 1 Iron oxide 2 China clay 2 Ethylene dichloride 24 Wax, per gallon of solution ounce By the process ofthis example, a record having a somewhat yielding core is provided. These records are relatively thin and may be rolled without injury, and in the pressing operation by which the sound grooves are formed a die of the flat type as distinguished from one of the crowned type should be used. If a record inaccordance with this invention is to be provided with a hard core, a landing pad of rubber, lead, or similar cushioning material should be used in the press.

The record forming operation is expeditedif the coated sheets are preheated before they are pressed. The preheating should, of course, be carried out at a temperature below that at which the resinous coating will tend to flow off or the core. tion is found in the thermo-plasticity of the playing surface, and unsatisfactory records or worn records may be repressed. It is also possible to make record blanks in accordance with this invention provided with a blank groove in which a sound track may be formedby means of a heated stylus or the like.

Further the records may be pressed in a multiple press, and when long sheets are used the records may be stamped or cut from the sheets as a part of the pressing operation, and the records may at the same time be pierced. Additionally, the records may be pressed under a reduced pressure as compared to that ordinarily used, and have a very low coefiicient of expansion.

Should cotton fiock be used in the records as a filler, it may first be impregnated with polymerized vinyl acetate or vinyl chloride dissolved in An advantage of the records of this invenethylene dichloride, and thereafter dried in a centrifuge. Of course it will be understood that cotton flock is more applicable to a solid stock record, or to the back stock of a laminated record comprising sheets connected by a core and having the record groove receiving compound on their outer surfaces.

In forming records in accordance with this invention, a roll of paper may be mounted in such a way that it can be unwound and drawn through a tank containing the primary coating solution as described above. Rollers or rods, or the like, may be used to keep the paper sub-, merged in the solution. The coated sheet may be drawn from the tank through a drier and thereafter rewound or passed directly to a second coating device where the second surface coating solution is applied. A satisfactory device for applying the-second coating is one in which the coating is applied simultaneously to both sides of he paper by means of brushes or the like.

on leaving the second coating machine, the paper may again be passed through a drier and it is then ready to be stamped into the form of records and pressed to provide sound record Having thus described the invention, what is claimed is:

1. A laminated sound record comprising a fibrous core at least the surface of which is impregnated with a hardened artificial resin to render the core moisture-resistant, and which is provided with a playing groove receiving surface containing as the sole resinous constituent a vinyl resin of the group consisting of polymerized vinyl esters of the lower fatty acids, vinyl halides, styrol and mixtures thereof, said record being characterized by durability and a minimum of surface noise.

2. A laminated sound record comprising a ficeiving surfaces integral with said core containing as the sole resinous constituent a vinyl resin of the group consisting of polymerized vinyl, esters of the lower fatty acids, vinyl halides, styrol and mixtures thereof, said record being characterized by durability and a minimum of surface noise.

3. A laminated sound. record comprising a fibrous core having at least its surfaces impregnated with a hardened heat-reactive artiflcial resin, and which is provided with playing groove receiving surfaces integral with said core containing as the sole resinous constituent a vinyl resin of the group consisting of polymerized v'inyl estersof the lower fatty acids, vinyl halides, styrol and mixtures thereof, said record being characterized by durability and a minimum of surface noise.

4. A laminated sound record comprising a fibrous core having at least its surfaces impregnated with a hardened heat-reactive artificial resin to render the core moisture resistant without rendaring it inflexible and incompressible, said rec- 0rd having a playing groove receiving surface integral with said core containing as thesole noise.

resinous constituent a vinyl resin of the group consisting of polymerized .vinyl esters of the lower fatty acids, 'vinyl halides, styrol and mixtures thereof, and said record being characterized by durability and a minimum of surface 5 noise. a 5. A laminated sound record comprising a fibrous core at least the surface of which is impregnated with a hardened artificial resin to ren der the core moisture resistant, and which is provided with a playing groove receiving surface containing as the sole resinous constituent a polymerized vinyl halide, said record being characterized by durability and a minimum of surface noise.

6. A laminated sound record comprising a fibrous core at least the surface of which is impregnated with a hardened artificial resin to render the core moisture resistant, and which is provided with a playing groove receiving surface 20 containing as the sole resinous constituent polymerized vinyl acetate, said record being characterized by durability and a minimum of surface RICHARD F. WARREN. 2's 

